While "씨/[Si]" is phonetically corresponding with "Mr." and "가/[Ga]" is phonetically corresponding with "Master", (male) Koreans/laborers jokingly use "가/[Ga]" only to (male) friends, since "가/[Ga]" can give negative feeling of slave or sham.

"군/[gun]" is (formally) used by (much) senior/elder persons in addressing or referring to (much) junior/younger male children or male teenagers."양/[yaŋ]" is (formally) used by (much) senior/elder persons in addressing or referring to (much) junior/younger female children or female teenagers.